Bates, the 21-year-old from Dunedin, belted six sixes and 19 fours in a swashbuckling 168 which came off just 105 balls. Together with Tiffen (100) she put on a record 262 runs for the second wicket as New Zealand posted a mammoth 373 for seven in 50 overs, almost 45 per cent of which came from boundaries.
In reply, Pakistan was bowled out for 150 in 48.1 overs, losing by 223 runs on the last day of the Super Six stage matches. For Pakistan, opener Nain Abidi top scored with 52 while New Zealand's Lucy Doolan bagged 3-30.
Meanwhile at the North Sydney Oval, Australia was hoping for a Pakistan victory to keep alive its slim hopes of making the final. But despite the disappointment of the Drummoyne result, Karen Rolton's side put in an impressive performance to end England's five-match unbeaten run in the tournament.
After bowling England out for 161, Australia comfortably achieved victory with 16.1 overs and eight wickets to spare.
On Sunday, England and New Zealand will go head-to-head in the final but on Saturday Australia and India, which defeated the West Indies by eight wickets, will square-off in the third/fourth place play-off at Bankstown Oval while on the same day at Drummoyne Oval, the West Indies and Pakistan will meet in the fifth/sixth place play-off.
By virtue of finishing in the top four, England, New Zealand, Australia and India have automatically qualified for the 2013 event to be staged in India while the West Indies and Pakistan have earned direct spots in the 10-team ICC Women's World Cup Qualifier 2011 where they will be joined by eight other sides -- two each from Asia, Africa and Europe, and one each from Americas and East Asia-Pacific regions, who will qualify from their own regional qualifying tournaments.
But the story of the day was Bates who was in a ruthless and punishing mood. Every stroke she played came right from the middle of the bat and always seemed to bisect the field. Such was her dominance that after reaching her century off 81 balls, she took just 18 more to reach 150.
The Pakistan bowlers, who had until today, put up decent bowling performances were completely at Bates's mercy while the fielders helplessly watched the ball disappear out of the park at regular intervals.
Bates was modest after her magnificent performance. She said: "We got off to a good start and the wicket was the best we've played on during this tournament. Haidee kept me ticking along and I seemed to be seeing the ball as though it was a lot bigger than it was.
"It was really enjoyable. I had been disappointed at the way I've gone up until today but it's good that I'm hitting form at the right time and hopefully I can carry it on into the next game.
"It was a huge boost to finish off a game like that. We haven't been so good at chasing runs in the past and it was a bit of a struggle out there. Today it was good to relax and let loose a little bit.
"I didn't know about too many records. I knew my own highest score and that was about it. I was told to hit sixes and keep my head still, so that was easy to concentrate on."
Bates joined Haidee in the fifth over and when she departed in the 40th over, New Zealand had well and truly sealed a place in the final as the scoreboard read 296-2 with still 10 overs remaining. Nicola Browne continued the good work of Bates when she hammered two sixes and two fours in a 22-ball 33 not out as New Zealand finished at 373 for seven in their 50 overs.
Bates's innings was the third highest individual score in ODIs after Belinda Clark's 229 not out against Denmark and Charlotte Edwards's 173 not out against Ireland, both in the 1997 World Cup in India.
The second-wicket partnership of 262 runs between Bates and Tiffen is the highest partnership in a World Cup, and the second highest of all time.
While Bates was clubbing the ball to all parts of the wicket, Tiffen was happily nudging and pushing the ball around to give her partner maximum strike. Tiffen was eventually out for exactly 100 after reaching her maiden century in her 116th ODI appearance.
At the North Sydney Oval in front of 2,214 spectators, England batted first after winning the toss and was bowled out for 161 in 49.3 overs with Claire Taylor once again amongst runs with a well-placed 49. Australia fast bowler Sarah Andrews was the pick of the bowlers with figures of 3-35 while Shelley Nitschke took 2-14 and Lisa Sthalekar bagged 2-31.
In its run-chase, Australia never looked back after a 79-run opening stand and comfortably reached the victory target in 33.5 overs with eight wickets still standing. All the batters contributed evenly with captain Karen Rolton top scoring with an unbeaten 41 that included four fours and two sixes.
At Bankstown Oval, leg-spinner Priyanka Roy took 4-14 as the West Indies was bowled out for 84 in 44.4 overs. In turn, India lost Anjum Chopa and Poonam Raut in the space of three balls but opener Sulakshana Naik (39 not out) and Mithali Raj (33 not out) helped India reach the target in 17.5 overs to give their team much-needed confidence ahead of the third/fourth place play-off against Australia.
Scores in brief:
At Drummoyne Oval, Sydney: New Zealand 373-7, 50 overs (Suzie Bates 168, Haidee Tiffen 100, Nicola Browne 33 not out; Naila Nazir 2-48, Sajida Shah 2-80)
Pakistan 150 all out, 48.1 overs (Nain Abidi 52; Urooj Mumtaz 27, Lucy Doolan 3-30, Sarah Tsukigawa 2-8, Nicola Browne 2-24)
Result: New Zealand won by 223 runs
At North Sydney Oval: England 161 all out, 49.3 overs (Claire Taylor 49, Lydia Greenway 22, Jenny Gunn 21; Sarah Andrews 3-35, Shelley Nitschke 2-14, Lisa Sthalekar 2-31)
Australia 162-2, 33.5 overs (Karen Rolton 41 not out, Alex Blackwell 38 not out, Leah Poulton 38, Shelley Nitschke 37)
Result: Australia won by eight wickets
At Bankstown Oval, Sydney: West Indies 84 all out, 44.4 overs (Stafanie Taylor 29, Pamela Levine 20; Priyanka Roy 4-14, Amita Sharma 2-14)
India 85-2, 17.5 overs (Sulakshana Naik 39 not out, Mithali Raj 33 not out)
Result: India won by eight wickets
Forthcoming matches:
21 Mar -- Australia v India (third/fourth place play-off), Bankstown
21 Mar -- West Indies v Pakistan (fifth/sixth place play-off), Drummoyne
22 Mar -- England v New Zealand (Final), North Sydney Oval
Points table:
| Team | Played | Won | Lost | Points | Net Run Rate |
| New Zealand | 5 | 4 | 1 | 8 | +1.37 |
| England | 5 | 4 | 1 | 8 | +0.82 |
| Australia | 5 | 3 | 2 | 6 | +1.11 |
| India | 5 | 3 | 2 | 6 | +0.99 |
| Pakistan | 5 | 1 | 4 | 2 | -2.14 |
| West Indies | 5 | 0 | 5 | 0 | -1.89 |
Photograph courtesy: International Cricket Council (ICC)